The present applicant has already proposed a display device in which a panel-shaped image-forming optical element and a display of a flat panel type are used to image-form a projected image of a video picture (such as a moving picture and a still picture) displayed on a display surface of the aforementioned display as a spatial two-dimensional video picture floating up in space over the image-forming optical element (see PTL 1).
As shown in FIG. 5, the aforementioned display device principally includes an image-forming optical element (micromirror array M) having an image-forming function, a flat panel display (display D) for displaying video pictures, and a case C or an open type housing for housing the image-forming optical element and the flat panel display. The micromirror array M is mounted in light-transmissive fashion in an opening provided in an upper surface (top plate portion) of the case C.
The display D is provided under the micromirror array M, and is supported by a mounting stand F, with a display surface Da of the display D inclined at a predetermined angle α (not less than 30 degrees and less than 90 degrees) with respect to a lower surface Mb of the micromirror array M. A video picture I (emitted light indicated by dash-double-dot lines) displayed on the display surface Da of the display D is image-formed through the micromirror array M as a two-dimensional video picture (spatial image I′) standing up obliquely in space over the micromirror array M (over an upper surface Ma) at a position symmetrical thereto with respect to the array M.